Danijel Vrbanc

Thank you Satamax for your observation.
I read the thread your send me. It shows the one of problems I have with the combustion process because of big smoke flew  resistance in transition area.
I have to do more spaces in the transition area from bell to the pipe.
At the end of weekend I will do some changes in doing more space.
I hope, I will have a good news with pictures of success.
Thanks again.

Hi Peter.
Thank you for your response to my post.
Well, obviosly, I have to do a lot of change to my reconstruction of RMH.
The reason I did this construction is the scrap material I had in my basement. (material costs was zero :))
Now I am very intersted in improvement of RMH so I have to invest to RHM. (I don't want to buy classic commercial heater with bad combustation).  
So first I want to prove that I will get the high temperatutre (good combustation) in my chamber.
Because diferences in cross section area of heat riser and flue (and pipes in the bench) I decide to reduce cross section area of heat riser to the same amount of both areas.
After that I will extend heat riser and bell for about 15 cm to get right proportional dimension 1:2:4
Do you think will it be a good idea?
The results will be published thru the pictures in the end of the next weekend.

P.S. I accepted your other remarks and I had idea for solving mistakes. First I want to get the right temperature. With no circulation in system, RHM operates like without heat exchanger.

Here are attached 2 pictures of  water heater construction I did in RMH.

And one correction from a previous post: The main proportions of my RMH are 1: 2: 3.5 (maybe that's the main problem - increasing the heat reiser by about 15 cm might solve the problem)

My English is not that good, but I hope you understand the text that follows.
A few months ago I started building a rocket mass heater.
I didn’t think much about the measures, the building materials, etc., well I built a rocket mass heater through one movie on Youtube that worked relatively well. ("Copy-Paste" method
After that I build the new version of the rocket mass heater with addition for water heating in the whole house. However, I got very poor combustion results. At the top of the oven I got only 220 degrees C.
I don’t know where the problem is, because the performance of this rocket mass heater is much worse than before.
I am sending pictures.
• The diameter of the heat riser is 16 cm.
• The depth of the firebox is about 30 cm.
• The distance between the top of the bell and the heat riser is 5 cm.
• The bell is 80 cm high and 57 cm wide.
• Without a bell, the rocket effect is very good, without smoke.
• The diameter of the flue is 13 cm and approximately 6 m long.
• Rocket mass heater is made in an approximate ratio of 1: 2: 4 (30: 60: 120 cm).
• Now, combustion of rocket mass heater is with smoke. This is the reason of low temperature.
• The water heater is made of a 3/4 "iron tube located in the insulation space wound around a heat riser (10 coils). This is not an ideal solution but with the temperature that the rocket mass heater should develop, it should be enough. (In in this version I get a radiator temperature of only 40 degrees C)
I kindly  ask for advice or a recommendation for a book or other sources that deals with this type of rocket mass heater. (I thing this is J type).